Systems have been implemented that have a power-saving function for electronic apparatuses such as televisions and personal computers, the function reducing consumed power by deciding whether a user is present based on existence or nonexistence of a user's operation, and controlling a power source in response to a result of the decision.
Other systems have been also implemented that reduce consumed power by deciding whether a user is present around an electronic apparatus using a human presence sensor, and controlling a power source in response to a result of the decision.
For example, PTL 1 describes a technique involving deciding whether a user is present based on information on existence/nonexistence of an operation by an operation input device provided in an electronic apparatus to control a power source of the electronic apparatus.
PTLs 2 and 3 describe techniques involving deciding whether a user is present based on a result of detection by a human presence sensor provided in an electronic apparatus to control a power source of the electronic apparatus.